Electrical control mechanism for fuel-oil burners



Oct. 5 1926. 1,602,363 J. c. JOHNSON ELECTRICAL CONTROL MECHANISM FOR FUEL ,C'IL BURNERS Filed Jan. 11, 1926 ll [FL-J 1 125 A L 7 7 C: 5 r, 26; 45 x 4 Z 7 Q39 13 INVENTOR;

A TTORNEYS.

l atente'd Oct. 5, 1926.

VUNHTED STATS .mssn c. JOHNSON, or OAKLAND, CALIFORNIA, ASSIGNOR r0 s. r. JOHNSON 00., or

. OAKLAND, CALIFORNIA.

ELECTRICAL CQNTROL MECHANISM FOR FUEL-0113.1 BURNERS.

Application filed January This invention relates to an electrical control mechanism for fuel oil burners of the rotary type, in which the operation is initiated or discontinuedaccording to the temperature of the room or other inclosure.

whose temperature is to be regulated.

) While not limited in application, my improved controlling system is more particularly designed for use in dwelling houses and is adapted for application to furnaces which may already be installed therein.=

One of the objects of the present invention is the provision of means for controlling the operation of an electric motor which operates the burner and supplies fuel and air for the purpose of combustion, through the medium'of a thermostat located in the room whose temperature is to beregulated. This object is effected by merely utilizing the thermostat as a medium for opening the circuit to an electro-magnetic control, operatively associated with the main circuit switch for the motor current.

Another object is the provision of means for controlling an electro-magnetic circuit, operatively associated with themain circuit switch for the motor current, through the medium of a boiler control means, responiivti, to conditions of temperature within the o1 er.

A further objectis to automatically stop.

the motor and the fuel oil supply system of the burner, when the controlling circuit 1s opened by a manually snap switch button.

Another object is to reduce the gas sup ply to the pilot frame,after a short interval of time when the burner is ignited,

Anotherobject is to shut down the burner system automatically if the fuel oil supplied to the burner has failed to ignite, or if the fuel oil supply should fail.

Other objects will be made manifest in the following specification of an embodiment of the invention illustrated in the accompanying drawings, in which:

Figure 1 illustrates an oil burning furnace equipped with my improved control mechamsm and Fig. 23: diagrammatic view of the electric circuit control mechanism of my invention.

. The operating current is obtained from.

' the conductors 11 and 12 to which the service wires 13 and 14 are connected by a double pole single throw main current switch 15.

Serial No. 80,659.

of supply'and the'burner, is connected in 1 I parallel by wires 21 and 22 to wires 13 and 14 respectively, of the motor circuit.

This fuel oil stop valve is preferably con trolled by the main circuit switch 15 in the electric circuit that operates the motor, the parts being arranged so that the said valve 'is held open to permit the flow of oil to the burner so long as the current passes to the motor and is closed to positively shut ofi the supply of oil to the burner when the motor stops. L

A wire 23 extends from the conductor ll to a room thermostat 24, illustrated diagrammatically, of any well known construction, which remains in a closed positionwhen cold or when the atmosphere at this placeis below a certain predetermined temperature, and opens to interrupt the circuit when the atmosphere at this place is above a cer tain predetermined temperature.

The thermostat 24, is connected in series by wire 25 to a boiler temperature controlled circuit breaker 26, illustrated diagrammati cally. This boiler controlled circuit breaker has connection with the steam header of the)" boiler and is arranged to flex its thermostatic member, when a" steam pressure above a predetermined maximum obtains. in the r netic gas valve 28, by way of wire 29, is an electrically operated time limit safety control 30. This time limit safety control comprises a heating coil 31,.a. thermostatic metal member 32, with one end secured at 33 and the other end bearing against a member 34. pivoted at 34'. The metallic member 32 partly surrounds the heating coil 31 and bends away from member 34 when heated.

Member 34 is connected through a flexible lead 35, having'contactor 36,.which is held against contactor 37, by the end of the thermostatic member 32, to wire 38. Wire 38 leading to the electro-magnetic coil -18 of near or adjacent to the electro-magnetlc control 17. A wire 40 leading from the electromagnetic control to conductor 12.

The series circuit then being complete, leading from conductor llby way of wire 23 through thermostat 24, wire 25 to boiler controlled circuit breaker 26, wire 27 to electro-magnetic gas valve 28, wire 29 to time limit safety control 30, wire- 38 to electro-magnetic coil 18 and by way of wire 40 to conductor 12.

The shunt out circuit for the electro-mag-.

netic gas valve 28, and to the time limit motor circuit, uninfluence safety control 30, comprises a branch wire 41, connected to and leading from wire 27 to the fire stack switch 42, a wire '43 extends from the stack switch 42 to the time limit safety control 30 and is connected at 33 with wire 44,-said wire 44 forming a shunt circuit between wire 33 and the member 34 of the time limit safety control.

Said shunt circuit being designed to carry its shunted proportion of the current necessary to retain a closed series circuit to! the electro-magnetic control, to retain the same in a closed position when the burner is ignited and operating.

This fire stack switch 42 is positioned where its thermostatic member is subjected to the heat from the burner, gases. When the burner has been ignited and has burned for a short interval, thethermostatic member of this stack switch will flggr to a circuit closing position, thus shunting out the circuit to the electro-magnetic gas valve 28 and to the heating element 31 of the time limit safety control 30. s

The action of the circuits including the operation of my burner control mechanism will now be described.

The closing of the circuit by means of the manually operated current control button snap sw1tch'39 completes the regulating circuit from conductor 11 by way of wire 23 to the thermostat 24, by. wire 25 to the boiler control 26,. by wire 27 to the electromagnetic gas valve 28, by wire 29 to the time limit safety control 30, by wire 38 to the electro-magnetic control 17 and by way of wire 40 to conductor 12.

This forms a' series control circuit .in

I which the breaking of any of the connections in the circuit would cause the entire circuit to become open and inoperative. This closing of the control circuit by button snap switch. 39 energizes the electro-magnetic coil 18 to draw controLelement 17 into enga ement therewith, also closing the double p0 e single. throw maincircuit switch 15,

flame of the pilot burner and the circuit to the motor. Theclosing of the motor circuit also operates to energize the v electro-magnetic fuel oil valve 20 and a .supply of fuel oil to the burner results.

The circuit to the motor is not connected in series with .the said series circuit, but directly controlled by this series circuit through the means of the 'electro-magnetic control 17, operatively associated with the maincurrent switch 15 .of the-motor circuit. The current supplycircuit to the motor is connected in multiple with the said control-.. ling series circuit.

By this arrangement the full current voltage becomes immediately available to operate the motor 19 and the fueloil stop valve 20, connected in (parallel with the by the said SBIIQS circuit.

This is of considerable importance in this invention.

It has been found in practlce to be of great advantage, in overcoming special difiiculties in the operation of an oil burning unit con ting of a larger flow of gas to the pilot burner to temporarily enlarge the flame thereof. The fuel oil supply issuing from the fuel oil stop valve being ignited by the enlarged v commences' heating the furnace.

The heat from the burner gases. soon bows the thermostatic member of the stack switch 42 to a closed position, closing the circuit between wires 41 and 43, thus shunting out the circuit by way of wire 27 to the electromagnetic gas valve. 28 and by way of wire 29 to the heating element 31 ofthe time limit safety control 30. Shunting out the circuit to the electro-magnetic gas valve 2.8 inthis manner causes the gas valve to close, thereby reducing the pilot flame to its normal condition.

The operating control complete from conductor 11 by wire 23 to thermostat 24, wire 25 to boiler control 26, from wire 27 by way of wire 41 to stack switch 42, wire 43 to shunt wire 44 and flexible lead-35 to contactors 36 and 37, wire 38 to the magnetic coil 18 and by way of wire 40 to conductor 12. a

With the burner now running steadily,

assume that an excessive steam pressure-is valve 28 beingenergized to open, permitv I circuit then being generated in the boiler, or the room atmosphere reaches a predetermined temperature. This will act upon either, the thermostatic control 24 or on the boiler control 26 to open their respective contacts, thus interrupting the control circuit, de-energizing the electromagnetic coil 18 of the control 17. This de-encrgizing of the coil 18 allows the con trol 17 to fall backwards by its own weight also removing with it the main current switch 15, operatively associated with the same, to an open position thus interrupting the circuit to the motor.

The fuel oil stop -valve chronously with the motor, it is opened simultaneously with the operation of the mo-' tor and is closed to positively shut off the supply of fuel oil to the burner when the motor stops.

The burner is now shut off. Meanwhile, the thermostatic members of the room thermostat or of the boiler control respectively. are cooling and contracting to the cold point or the closing position, the burner will remain in a shut off condition, until the undesirable conditions in the boiler are corrected, or the temperature of the room has lowered. The gradual lowering of the pressure within the boiler, or a reduced room temperature will eventually complete and close again the control circuits through the thermostat 21 or through the boiler control 26.

This completion of the control circuit will again automatically close "the electro-magnetic control 17 including the main current switch to again operate the motor including the fuel oil valve, while at the same time an enlarged flame from the pilot burner will again ignite the fuel oil.

But should there beno ignition of the burner for any reason whatever, as when there is no fuel, or the fuel delivered should fail to be ignited, if for any reason the gas pilot has blown out, there would be no resulting increase in temperature within the furnace and the thermostatic member of the stack switch 42 would receive no heat and consequently would fail to move to a circuit closing position.

The current taken to operate the electromagnetic control 17 would continue to pass through the time limit safety control 30 and particularly through the heat coil 31. Meanwhile, the metallic member 32 of the time limit safety control 30 being heated by the heat coil 31, bends towards heating coil 31 1 and frees member 34, thereby interrupting the control circuit between contactors 36 and 37 resulting in de-energizing of the electro-magnetic coil 18 of the control 17 opens switch and stops the burner mechanism. A manual reset is required after thermostatic member 32 has cooled before the circuit can again be closed automatically. This manual operates syn- '1 am aware that various forms of thermostatic controls have been used commercially for diverse purposes, and I do not claim these individual controls in detail.

\V-hat I claim and desire to secure by Lei.

ters Patent is: v

1.- In an electrlcal control mechanism for fuel 01 burners having, in combination, electric current conductors, a motor for rotating the burner, a circuit connectlon between the motor and the current conductors, a main circuit switch for the motor, an electro-magnetic control circuit in multiple with the motor circuit operatively connected with said main circuit switch for controlling its operation, an electro,-magnetic fuel oil stop valve connected in parallel with the motor circuit, in a series circuit with the said electro-ma'gnetic control a time limit safety control, an electro-magnetic gas valve, a

boiler controlled means for opening the circuit to said electro-magnetie control under predetermined boiler cond1t1ons so as to substantially de-energlze the electro-magnetlc control to open the main circuit switch to, interrupt the'motor circuit and then again" under predetermined condition to close said circuit to re-energize said electro-magnetic control to close the main circuit switch to again operate the motor, a temperature actuated stack switch, consisting of a thermostatic member located in the burner stack, arranged to be open when cool and to close when said member is heated, said stack switch being so connected in said series circuit as to shunt out the electric circuit to the electro-magnetic gas valve and to the time limit safety control when the burner is ignited.

2. In an electric control mechanism for fuel oil burners having, in combination, electric current conductors, a motor for rotating the burner, a circuit connection between the motor and the current conductors, a main circuit switch for the motor,'an electromagnetic control circuit in multiple with the motor circuit operatively connected with said main circuit switch for controlling its operation, an electro-magnetic fuel oil stop valve connected in parallel with the motor circuit, in a series circuit with the said electro-magnetic control a time limit safety control, an electro-magnetic gas valve, a boiler controlled means for opening the circuit to said electro-magnetic control under predetermined boiler conditions so as to substantially de-energize the electro-magnetic confuel oil burners having, in combination,

tric current supply conductors, a motor for operate the motor, a temperature actuated stack switch, consisting of'a thermostatlc metal member located in the stack, arranged to be open when cool and to close when said,

member is heated, said stack switch being so connected in said series circuit as to shunt out the electric circuit to the 'electro-magnetic gas valve when the burner is ignited.

3. In an electrical controlmechanism for circuit, in a series :circuit with the said elec-.

tro-magnetic control, a time limit safety control, an electro-magnetic gas valve, a boiler controlled means for opening the circuit to said electro-magnetic control under predetermined boiler conditions so as to substantially de-energize the electro-magnetic. control to open the main circuit switch to interrupt the motor circuit and then again under predetermined condition to close said circuit to re-energize said electro-magnetic control to close the main circuit switch to again operate the motor, a temperature actuated stack switch, consisting of a thermostatic metal member located in the burner stack, arranged to be 0 en when cool and to close when said mem er is heated, said stack switch being so connected in said series circuit as to shunt out the electric circuit to the time limit safety control when the burner is ignited.

4. In an electric control mechanism for electric current supply conductors, a motor for rotating the burner, a-- circuit connection between the motor and the current conducelectro-magnetic control circuit'in multiple 'with the motor circuit operatively connected with said main circuit switch forcontrolling its operations, an electro-magnetic fuel oil stop valve connected in parallel with the motor circuit, in a series circuit with the said electro-magnetic control, a time limit safety control, an electro-magnetic gas valve and thermostatic operated means for controlling the circuit to said electro-magnetic control between desired limits of temperature so as to substantially de-energize the electro-magnetic control to open ,the main circuit switch to interrupt the motor circuit when the 2 temperature passes the desired limit and then again, when the temperature falls below the desired limit to re-energize said electro-magnetic control to again close the main circuit switch to the motor, a temperature-:.act-uated, stack switch, consisting of a thermostatic member located in the burner stack, arranged to'be open when cool,

forming, when closed by heat from the burner a shunt out circuit around the electro-magnetic gas valve and the time limit safety control, so as to shunt out the electro-magnetic gas valve and the time limit safety control when the burner is ignited.

5. In an electrical control mechanism for fuel oil burners having, in combination, electric current supply conductors, a motor for rotating the burner, a circuit connection between the motor and the current conductors, a main circuit switch forthe motor, an electro-magnetic control circuit in multiple with the motor circuit operatively connected with said main circuit switch for controlling its operations, an electro-magnetic fuel oil stop valve connected in parallel with the motor circuit, in a series circuit with the said electro-magnetic control a time limit safety control, an electro-magnet-ic gas valve and thermostatic operated means for controlling the circuit to said electro-magnetic control between desired limits of temperature so as to substantially de-energize the electromagnetic control to open the main circuit switch to interrupt the motor circuit when the temperature passes the desired limit and then again, when the temperature'falls below the desired limit to re-energize' said electro-magnetic control to again close the main circuit switch to the motor, a temperature actuated stack switch, arranged to be; open when cool, forming, when, closed by heat from the burner a shunt circuit around the electro-magnetic gas valve so as to shunt out the electro-magnetic gas valve when the burner is ignited. i

6 In an electrical control mechanism for fuel oil burners having, in combination, elecrotating the burner, a circuit connection between the motor and the currentconductors, a main ClI'Clllt swltch for the motor, an electro-magnetic control circuit in multiple with the motor circuit op eratively connected with said mainv circuit switch for controlling itsoperations, an electro-magn'etic fuel oil stop valve connected in parallel with the motor. circuit, in a series circuit with the said elec-' tro-magnetic control a time limit safety control, an electro-magnetic gas valve and thermostatic operatedmeans for controlling the circuit to saidelectro-magnetic control between desired limits of temperature so as to substantially deenergize the electro-magnetic control to open the main circuit-switch, to interrupt the motor circuit when'the'temperature passes the desired limit and then again, when the temperature falls below the desired limit to re-energize said electromagnetic control to agam close the main circuit switch to the motor, a temperature actuated stack switch, arranged to open when cool, forming, when closed by heat from the burner a shunt circuit around the time limit safety control so as'to shunt out the time limit safety control when the burner is ignited.

7, In an electrical control mechanism for fuel oil burners having, in combination, an electric current supply, a motor for rotating the burner, a circuit connection between the motor and the current supply, a main circuit switch for the motor, an electro-magnetic control circuit in multiple with the motor circuit operatively associated with said main circuit switch for controlling its operation, an electro-magnetic fuel oil stop valve connected in parallel with the motor circuit, in a series circuit with said electromagnetic control a thermostat for controlling the series circuit to said electro-magnetic control between desired limits of temperature and controlling means responsive to boiler conditions for breaking the circuit between said thermostat and the said electromagnetic control for rendering the operation of the motor and of the fuel oil stop valve means dependent upon boiler conditions.

8. In an electrical control mechanism for fuel oil burners having, in combination, an electrical current supply, a motor for operating the burner, a circuit connection between the motor and the current supply, a main circuit switch for the motor, an electro-magnetic control circuit in multiple with the motor circuit operatively associated with said main circuit switch to control its operation, an electro-magnetic fuel oil stop valve connected in parallel with the motor circuit. in a series circuit with said electro-magnetic control, controlling means responsive to boiler conditions for opening and closing the circuit to said electro-magnetic control, a thermostat for breaking the circuit betweeri said vboiler controlled means and the said electro-magnetic control between desired limits of temperature and for rendering the operation of the motor and of the fuel stop valve dependent upon temperature conditions.

9. .In an electrical control mechanism for fuel oil burners having, in combination, electric current conductors, a motor for rotating the burner, an electric circuit connection between the motor and the conductors, a main circuit switch for the motor, an electro-magnetic control circuit in multiple with the motor circuit operatively associated with 'the main circuit switch to open and close the same, an electro-magnetic fuel oil -stop valve connected in parallel with the motor circuit, an electro-magnetic gas valve,. an

electrically actuated heat coil and a pair of contactors all connected in series with the said electro-magnetic control circuit, a thermostatic metal member in proximity of the heat coil to hold the contactors together A when said member is cool, but to permit the contactors to separate and de-energize the heat coil when said 'member is heated and means for shunting out the electro-magnetic gas valve when the burner is ignited.

10. In an electrical control mechanism for fuel oil burners having, in combination, electric current conductors, a motor for rotating the burner, an electric circuit connection between the motor and the conductors, a main circuit switch for the motor, an electro magnetic control circuit in multiple with the motor circuit operatively connected withthe main circuit switch to open and close the same, an electro-magnetic fuel oil stop valve 11. In an electrical control mechanism forfuel oil burners having,"in combination, elec-' tric current conductors, a motor for rotating the burner, an electric circuit connection between the motor and the conductors, a main circuit switch for themotor, an electro-magneti'c control circuit in multiple with the motor circuit operatively connected with the main circuit switch to open and close the same, an electro-magnetic fuel oil stop valve connected in parallel with the motor circuit, an electro-magnetic gas valve, an electrically actuated heat coil and a pair of contactors, all connected in series with the electro-magnetic control circuit, a thermostatic metal member in proximity to the heat coil to hold the contactors together when said member is cool, but to permit the contactors to separate and break the circuit when said member is heated to de-energize the electro-magnetic control and open" said main circuit switch upon failure of said electro-magnetic fuel oil stop valve to operate, resulting in failure of the burner to ignite.

12. In an electrical control mechanism for fuel oil burners havi'n'g, in combination, a motor for rotating the burner,-an electric circuit connection to said motor, a main circuit switch for said motor, an electro-magnetic control circuit in multiple with the motor circuit operatively connected with said main switch to open and close thesame,

an electro-magnetic fuel oil stop valveconnected in parallel with the motor clreuit, m a series circuit with the electro-magnetic control an electro-magnetic gas valve, an elecan electrically ing a shunt connection between them, a thermosta-tic metal member in proximity to they heat coil to hold the contactors together 5 when said member is' cool, but to permit the contactoi's to separate when said memberis heated, the shunt connection between the saw contactors being designed to carry its shunted proportion of the current necessary to retain the elective-magnetic control circuit Wm in a closed position when the burner is ig- 1 nitefl. o

In testimony whereof I afix my si eture.

y JESSE G, JOHN UN. 

